Dear Alex,
Thank you for your input.
Am 22.10.25 um 14:06 schrieb Loktionov, Aleksandr:
-----Original Message-----
From: Paul Menzel <[email protected]>
Sent: Wednesday, October 22, 2025 1:49 PM
Am 21.10.25 um 17:44 schrieb Robert Malz:
From: Jay Vosburgh <[email protected]>
Multiple sources can request VF link state changes with identical
parameters. For example, Neutron may request to set the VF link state
to
What is Neutron?
IFLA_VF_LINK_STATE_AUTO during every initialization or user can issue:
`ip link set <ifname> vf 0 state auto` multiple times. Currently, the
i40e driver processes each of these requests, even if the requested
state is the same as the current one. This leads to unnecessary VF
resets and can cause performance degradation or instability in the VF
driver - particularly in DPDK environment.
What is DPDK?
I think Robert needs:
- to expand acronyms in the commit message (Neutron → OpenStack Neutron, DPDK →
Data Plane Development Kit).
- to fix the comment style as per coding guidelines.
- add a short note in the commit message about how to reproduce the issue.
@Paul Menzel right?
Correct.
Maybe also mention how to force it, as there seems to be such an option
judging from the diff.
With this patch i40e will skip VF link state change requests when the
desired link state matches the current configuration. This prevents
unnecessary VF resets and reduces PF-VF communication overhead.
Add a test (with `ip link …`) case to show, that it works now.
Co-developed-by: Robert Malz <[email protected]>
Signed-off-by: Robert Malz <[email protected]>
Signed-off-by: Jay Vosburgh <[email protected]>
---
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 081a4526a2f0..0fe0d52c796b 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -4788,6 +4788,7 @@ int i40e_ndo_set_vf_link_state(struct net_device *netdev,
int vf_id, int link)
unsigned long q_map;
struct i40e_vf *vf;
int abs_vf_id;
+ int old_link;
int ret = 0;
int tmp;
@@ -4806,6 +4807,17 @@ int i40e_ndo_set_vf_link_state(struct net_device
*netdev, int vf_id, int link)
vf = &pf->vf[vf_id];
abs_vf_id = vf->vf_id + hw->func_caps.vf_base_id;
+ /* skip VF link state change if requested state is already set */
+ if (!vf->link_forced)
+ old_link = IFLA_VF_LINK_STATE_AUTO;
+ else if (vf->link_up)
+ old_link = IFLA_VF_LINK_STATE_ENABLE;
+ else
+ old_link = IFLA_VF_LINK_STATE_DISABLE;
+
+ if (link == old_link)
+ goto error_out;
Should a debug message be added?
I think adding one would be redundant since skipping identical state
changes is expected behavior.
My thinking was, if something does not work as expected for a user, like
issuing the command to force a reset, that it might be useful to see
something in the logs.
+
pfe.event = VIRTCHNL_EVENT_LINK_CHANGE;
pfe.severity = PF_EVENT_SEVERITY_INFO;
Kind regards,
Paul
